We've seen picture of fixed (8, 16, 32, 64) ND filters so I think those are coming and will be an optional extra at some point.
If you mean the electronic variable ND that was rumoured not being ready, I'm not sure it even exists.
The trouble with leaked DJI info is that it always comes from China and so much gets mixed up in translation.
At this stage, to me the variable bit sounds most likely to mean the various lens filter density is different to give the same strength ND effect on all three lenses like the Freewell ones. There doesn't seem to be any electronic contacts on the filterless gimbal images we've seen and if it's an unreleased built in future feature why would you need optional clip on ones.
However, this might change tomorrow as we get closer to launch so its anyones guess.